Thieves who break into moving vans, tractor trailers and other cargo containers use a variety of tools such as sledge hammers, acetylene cutting torches, saws, grinders and the like. The bolt cutter is a favored tool of burglars for cutting padlocks because of its portability and reduced time, light and sound generation; thus there is a need to protect padlocks used on containers, moving vans, semi-trailers, truck trailer units and storage facilities. Tractor trailers with twin rear doors are secured by a pair of vertical stanchions, at least one of which has a locking handle or lever, which is normally secured by padlock to prevent rotation of the stanchion, thus maintaining the doors in a locked condition. It is also desirable to provide protection for padlocks securing similar operating levers of doors of containers or storage facilities. It is desirable to keep the lock guard relatively small to make it more difficult for thieves to access the lock. Additionally, it is important to some container owners, due to the high value or sensitivity of their loads, to shield the retainer catch and pivoted locking latch because those components can be cut to gain entry while leaving the lock untouched.